In the oil and gas industry, in order to access hydrocarbon-bearing or geothermal formations, one or more bores may be drilled from surface, the bores typically being lined with sections of metal tubes, known as casings. A number of casings are coupled together as a casing string, the string being run into the bore substantially without rotation. The annulus between the casings and the bore is subsequently filled and sealed with cement to secure the casings in place.
When running the string into the bore, the string commonly encounters obstructions in the bore including, for example, ledges extending into the bore, partially collapsed regions of a formation, or drill cuttings lying on the lower side of an inclined bore, whereby the bore obstructions may prevent or limit further formation, completion or operation of the bore. In order to improve the surface texture and geometric tolerances of the bore, a reaming tool may be attached to a leading end of the string and run into the bore to facilitate removal of the obstructions, this known as a reaming-with-casing operation. The casing string is reciprocated and/or rotated from surface to permit a reaming operation to be performed. However, casings and casing couplings are generally not suited to transferring torque and rotation of the casing string may be limited. Furthermore, rotating the casing string greatly complicates the drive and coupling arrangements required at surface.